1. Field of the Invention
This invention relates to an apparatus for cleaning the end of a pipe prior to welding; more particularly, the device of the present invention relates to a mechanical abrasive-blast machine of the type having a blasting head receiving the workpiece therein and having abrasive material supplied under pressure to said blasting head, and is so designed that the abrasive material can be removed from the blast head by suction.
2. Description of the Prior Art
The abrasive blast cleaning of the end of pipes prior to welding has generally been a manual operation. In Conover, U.S. Pat. No. 3,352,062 (1965), a sand blast device was disclosed wherein a blasting chamber completely encircled the end of a pipe to be blast-cleaned. A plurality of ports were provided for the injection of air which was to pick up previously introduced abrasive material and impinge the abrasive material against the pipe, thereby cleaning it. This system would seem to prove deficient in several respects, the first being chance abrasion of the entire surface to be welded, because of the limited number of injection ports. Secondly, Conover anticipates that his disclosure may be deficient and might require the device (which is normally non-rotatable) to be rotated manually around the pipe in order to insure the entire area will be efficiently blast-cleaned by the abrasive material. The current invention provides for a smaller blasting chamber which has a greater and localized blasting effect with mechanical means for rotating the blasting chamber with respect to the entire circumferential edge of the pipe to be cleaned.